There is no uranium isotope with 234 neutrons. The questioner almost certainly meant the uranium isotope with 234 nucleons, which is a naturally occurring isotope U234 otherwise element 92, with 142 neutrons.
In which case its half life would be 252,000 years.
This is the isotope plutonium-238: 23894Pu.
Uranium 235.
This isotope is uranium-238: 23892U.
Uranium 234 - 234U.
235U or uranium 235
This the isotope uranium-236.
This is the isotope plutonium-238: 23894Pu.
Natural uranium is only 0.72% fissile uranium-235 isotope. This is only fissionable when using heavy water as the moderator to slow the fission neutrons. With any other moderator you need 3% to 5% uranium-235 isotope. For unmoderated fast neutron reactors like breeders you need 20% to 95% uranium-235 isotope.
The most common isotope of uranium, 238U, has a poor cross-section (the ability to assimilate neutrons) for slow neutrons. In order to enhance the reaction, we enrich the uranium to 235U, from a natural level of about 0.7% to about 4%. This enhances the ability of the uranium to participate in a fissile reaction, i.e. one that sustains neutrons that fission atoms which creates neutrons, etc.
Uranium atoms (no matter which isotope) ALL have the same number of protons 92. it is in the umber of neutrons that changes between the isotopes.
Uranium-237 has 145 neutrons.
Uranium-235 is a natural isotope with 143 neutrons. Uranium-231 is an artificial isotope with 139 neutrons.
The atomic number of uranium is 92. The number of neutrons of the isotope uranium-235 is 143.
Uranium-238 has 146 neutrons.
The most common isotope of uranium is uranium-238 with 146 neutrons.
146 neutrons.
93Np237 isotope has 144 neutrons (237 - 93 = 144)
Uranium has 92 protons and electrons; the number of neutrons is different for each isotope: number of neutrons = atomic mass of an isotope - atomic number of uranium (92)
And what is the question?
143 neutrons
This is the isotope plutonium-238: 23894Pu.
Uranium-235 has 143 neutrons; uranium-238 has 146 neutrons. Each isotope has a different number of neutrons.
The isotope plutonium-239, which is synthesized from uranium, has 94 protons (like all isotopes of plutonium) and 145 neutrons in its nucleus. Use the link below for more information on plutonium.